#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main() {
    int a = 0, b = 0, c = 0;
    scanf("%d %d %d", &a, &b, &c);
    if (c % b)
    {
        printf("%d", a - c / b - 1);
    }
    else {
        printf("%d", a - c / b);
    }
    return 0;
}
